Improvement in processes and apparatus for extracting essential oils



G. G. PERGEVAL.

Process and Apparatus for Extracting Essential Oils.-

No. 133,719, Patented 0e .1o.,1a72.

' wn'nssssst 1 aw/a/%M INVENTOR;

,4"? PHUTU-UTHOGRAPHIC L'OMY 'OSBORNES PROCESS) 1vrrED STATE GEORGE e.PERGIVAL, or WATERVILLE, MAINE.

' IMPROVEMENT IN PRGCESSESAND APPARATUS FOR EXTRACTING ESSENTIAL OILS.

To all whom it may concern:

Be it known that I, GEORGE GILMAN PER- CIVAL, of Waterville, in thecounty of Kenimprovement in the process of extracting essential oilsfrom the substances naturally containing them. I According to thisimprovement, instead of boiling the charge with water, or of simplypassing steam through charge, with or without previous maceration incold water, as is commonly practiced, I firstjtreat the charge withboiling or very hot water, and then draw off this hot water andextractthe oil by passing steam through charge. This preliminarytreatment with hot water softens or acts upon the charge in such amanner that steam will extract the oil more readily than before suchtreatment. This preliminary treatment with hot water may be in either ofthe following ways: First, I may boil the charge a short time withwater, or macerate it a longer time with hot water, and then draw offthe water; or, second, I may percolate or dreneh the charge with boilingor hot water, and then stop percolating and draw off water. I prefer thelatter mode, as being more convenient in practice, and while passingsteam through charge I prefer to let a little boiling water trickle downthrough. charge, just enough to keep it'moistene'd. The object of thispartof the invention is to extract by steam oils from 'certainsubstances usually distilled with water. Thisprocess is especiallyadapted to charges more or less dry, andI claim for it no advantage withperfectly fresh charges of herbs which. like peppermint, cedar, &c.readi- 1y yield their oil to steam while fresh.

I do not claim any preliminary treatment vith coldwater; nor do I claimextracting oil 'from charge by passing steam through it, un-

less such charge has been previously treated with hot water and the hotwater drawn off.

The second part relates to giving to the steam used to extract the oil acirculatory motion, so, that thebulk of the steam may pass through thesame charge more than once, in-

stead of once, as in the common process, of extracting oil ofpeppermint. The obj ectis to obtain a greater percentage of oilin thedistillate. In the common process, wherethe steam is passed through thesame charge, but once, it is seldom, if ever, perfectly saturated withthe vapor of the oil, and for this reason is frequent] y passed througha second charge. The third part relates to cooling the exhausted chargeby drawing air down through it. The object is convenience in unloading.As the steam and hot-air are drawn down andaway from the workmen thestill may be unloaded with less inconvenience than .where the steam andhot air rise from the top of the still. The fourth part relates to thecombination of a still for extracting essential oils and a device forimparting to the steam the circulatory motion" mentioned in the secondpart. I call such a device a steam-circulatory The fifth part relates tothe combination of a still for extracting essential oils a-nda devicefor drawing the air down through the exhausted charge. I call suchdevice a cooler. The sixth part relates to the combination of one ormore stills for extracting essential oil and a hydraulic main similar tothose in common use in gas-works. The object of the combination is toenable several stills to be used with one condenser without connectingand unconneeting the pipes.

The present application is a subsequent improvement on patents Nos.110,998 and 120,596, issued to me January 17 and November 7, 1871, and Ishall describe, but not claim, some of the combinations covered by saidpatents.

I General Description.

Figure 1 represents two similar stills with attachments. The right-handone is in vertical central section along line :0 as, Fig. 1, whiledistilling. The left hand one is in front elevation, with coolerattached, while cooling exhausted charge. Fig. 1, plan of same; Fig.

1 side elevation of same; Fig. 2, vertical cen- I tral section ofmodification.

Similar letters of reference indicate like parts. Single-barbed arrowsrepresent direction of water in distilling; double-barbed ones, thedirection of steam impregnated with vapor of oil; triple-barbed ones,the direction of current of air in cooling exhausted charge. Descriptionof Fig. l.A-A represent the still-bodies, of which there may be one ormore. They are wooden tanks, seven feet high, tive feet wide at top, andthree and one-halffeet at bottom. The cover a is movable, and canberendered tight by oakum or other suitable packing. b is a perforatedfalse bottom, eight inches above true bottom. B is a six-inch coppertube, conveying the impregnated steam from A to hydraulic main G. O isequivalent to the device of the same name used in gas-works, and answersthe same purpose. It will be seen that several pipes, B, B, and B, fromas many difi'erent stills, terminating below the surface of the water inthe same vessel 0. D is a six-inch pipe conveying the impregnated steamfrom (J to the condenser, not shown in the drawing, but like those incommon use. 0 c are perforated movable copper caps placed on ends of BandE during distillation to keep out portions of charge. dis perforatedfalse bottom to O. c is siphon-tube for filling G, not shown in drawing.f, a sliding overflow-tube to regulate amount of liquid remaining in G;g, handle to same passing through steam-tight packing in cover of (J.

E and F together constitute the steam-circulator. E is an eight-inchcopper tube, of shape shown. It is provided with a sliding gate, h,

and a pressuregage, 0', consisting of a bent glass tube with bend filledwith colored water.

F is a steam -jet connected by tube 7 witha steam-boiler furnishingsteam at a pressure of forty pounds to square inch, more or less. It ispreferable to have F so constructed that the orifice may be adjustable.When used for circulating steam, with an open charge like cedar,one-fifth inch or one-quarter inch orifice will do, but with morecompact charges, or when used to heat water, a larger orifice isdesirable. This jet is so placed that the escapin g cone of vapor shalljust fill the contracted end of E and cause a downward draft in E, as insteam-jet ventilators. k is a four-inch tube with cock, used only when Iheat water in A by jet F. l is a four-inch pipe with cock to completelyempty still. The pipes l l of a series of stills are connected with pipem. One end of m terminates in a waste-cock. The other end is closed, buta branclrwith cock (cocknot shown in drawing) terminates in a tallvessel in G, forming a steam-trap. G is a wooden tank, same size as A,with permanent cover. B is apipe for conveying impregnated steam from Gto (J. B has a gate, h, and from below this gate may send branches B B,each with gate It", to tanks A A. H is a coil of one and one-fourth inchcopper or lead pipe, with cock at each end. H is used mainly to heat andboil water in G, and is supplied with steam by pipe j.- The condensedsteam is drawn oil by a small cock at lower end. With expensive oils itis sometimes desirable to cool the water in G. This can be accomplishedby pouring cold water into tube J, connected with lower end of H. I is acentrifugal'pump placed a little lower than G, and capable of fillingthe two-inch pipe 01.. This pipe n runs horizontally back of and aboveseries of stills. Connected: with n by a cock and union. is a branch, 0,to each still. This branch 0 is per manently connected with cover a, andimpinges on a metallic plate under this cover so placed as to scatter orsprinkle the water over top of charge.

' The tank G corresponds to oil extractor B in above-mentioned patent,No. 120,596, Z to c, m to d, I to O, n to k, and o to 11, same pat'ent.I do not here claim any of the combinations there patented.

K is an eight-inch pipe, used only to cool exhaustedcharge.Itconnectstop of E with chimney or stove-pipe L, fitting tightly intothimble in L. One pipe, L, will answer for a series, and the taller thebetter. 19 is a steam-jet for starting a current in'- L. Where we haveother means of starting the current it may be dispensed with. q,air-cock; M, charge in still. I may have a. pressure gage so constructedas to let air into still A whenever there is a partial vacuum-not shown.All parts should be well protected from loss of heat by radiation.

To use, I vary the process with the age of the charge:

First, suppose I have a perfectlyfresh charge of cedar, out within a fewhours. As I claim no advantage for the first part of this invention, inthis case I do not use it; nor do I use the parts B B G H 1 J k it, nor0. I use land m only to let out water condensed in heating charge. Whencover is properly packed I let on steam by jet F. This jet of steamdraws down through E a current of the impregnated steam, which hasalready passed up through charge, and forces it up through again.Icontinue this until the charge is exhausted. The bulk of steam in thestill circulates round and round, and most of it passes through the samecharge several times. This illustrates the second part of .my invention,and the combination of A with E and F illustrates the fourth part.

I can at any time test the action of the steam-circulator by closinggate h and observing 1'. When charge is exhausted I remove cover a andconnect E with L by K in manner shown. If a current of heated air doesnot start spontaneously in L I start one by the temporary action of jet1;. A'current of the cold surrounding air is then drawn down through theexhausted charge, cooling the charge; but itself, becoming warmed andrising through E, escapes by the top of L, carrying with it most of thesteam given off by the cooling charge. This current, once started, willcontinue until the charge is cooled, or until the air ceases to bewarmed in its down-- ward passage through still. This downward passageof air illustrates the third part of my invention, and the combinationof A wit-h E, K, and L, the fifth part.

Second, in case I have a charge quite dry-e. 9., cedar three monthso1d-I employ the first part thus; After maceration in cold water I givecharge a preliminary treatment with boiling or hot water. Thispreliminary treatmeme 1 a ment maybe by percolating or by boiling. Iwill describe by percolating first. .Let the cold water of macerationinto G, heat it by steam- .coil H, and in the meantime run pumpl at fullspeed. This forces water up a, down 0,

and drenches charge .with the gradually-heated water In time both chargeand water are heated to 212, and steam escapes by B to 0. Then I'cutdown steam from H, leaving on a little to supply loss of heat byradiation, and continue this percolating or drenching an hour,

more or less, depending upon nature and dryness of charge. Then I stopthe drenching,

:lettin g out all the water in A, and let on steam by jet- F. 1 At firstthe oil comes over quite vfast,but in time the percentage in distillate.diminishes. I then shut off steam from F and drench again a shortertime than before-say fifteen minutes; then steam again. The oil againcomes quite rapidly for a time, and then the percentage in distillateagain diminishes. -I repeat the drenching,and so proceed, alternatelydrenching and passing steam through, until charge is exhausted. Insteadof these alternate drenchings and steamingsyafter the chargeisthoroughly drenched and softened, in the first place I may,simultaneously with passing steam through, percolate with a littlewater-just enough to trickle down through charge and keep it Wet, butnot enough to interfere with the circulation of the steam. I canregulate this amount by cock in 0. This illustrates the first partof myinvention.

When it is decided to perform the preliminary treatment by boilinginstead of percolating ordrenching, I proceed as follows: I let on steamby F to A, containing charge and water of maceration, closing gate h-andopenin g cock is. When charge is sufficiently softened Ilet out waterand extract oil from charge by steam, as above. At first, oil comes rapidly and then in less quantity, and I pump up the water and give it ashort boil at intervals until'charge is exhausted. Exhausted charge iscooled as before. I

1 Third, in case I have cedar slightly driedsay out two weeks-I mayproceed as in second case where I have quite dry cedar; but I preferfirst to proceed as in first case where I have fresh cedar,steamingwithout any pre-' yields an oil quite soluble in hot water, Iprefer to extract about three-fourths of the oil by the processdescribed and patented in said patent No. 120,596, and the last part ofthe oil by the first part of this invention,- as follows: .Maceratecharge in cold water and let this down into G. I heat and boil thiswater bysteamcoil H, running pump I continually 'full head untilaboutthree-fourths of oil are extracted.

The water extracts the oilfrom charge, carries it to G, and there givesit off to steam generated by steam-coil H. This steam passes via B to 0,(according to process more fully described in said patent.) I then stopor very much diminish the currents of water, so that only a little willtrickle down through charge, and shut off most of the steam fromeoil H.I pass the steam generated in G m'a B and B into bottom of A, and let onsteam to jet F, and proceed as first above described.-

Ohemicals, such as salt, acid, alcohol, &c., may be added to water usedin preliminary treatment. I generally use none, but use the same waterover and over, cooling it to macerate fresh charges without exposing itto air, by pouring cold water through coil H by pipe J. For cheap oils,like cedar, the hot water remaining from previous operations may be usedfor maceration. A little fuel is thus saved, but I think at the expenseof a little oil.

Modifications.

Description of Fig. 2.This represents a still requiring no pump A, as inFig. l, but one foot deeper. False bottom bis two feet above truebot-tout B proceeds from under this false bottom, but has a branch, 1,with gate connecting itwith top of A. E, similar to E in Fig. 1, butreversed in position, so as tocause a circulating current down throughcharge. F need not be adjustable, and can be placed in lower part of E,pointing up, if desired; 0, shelf to keep water out of E. n, H I, aj,and 0 j, together constitute a heater, as describedin Fig. 1, saidpatentNo. 110,998, (a corresponding to g, steam-jet HIto 0, nj to cl,andojtofin said figure.) Steam-jet H I draws the water down n, heats andboils it, forces it up a j 0 j, and discharges it on top of charge. (Asit thus answers the purpose of both H andI in Fig. 1, I have given itthe double lettering.) l, pipe for completely emptying still; 8,overflow-tube, with cock so placed as to retain about twelve inches ofwater in A. K, indicated by dottedlines,.is atube used only in coolingexhausted charge. One end fits int] and the other may terminate in anywaste space-e. 9., pass through side of building. q

To use with a dry charge, like cedar,I macerate andthen open cock in 8,drawing off water to level of this tube. I then let on steam by jet H-I, using a large' orifice, until the water and charge are heated to2129, when I diminish orifice. The gates in E and 1" being closed thesteam and water both pass down through charge.

This illustrates the first part of my invention, (drenching and passingsteam through alternately or simultaneously,) and differs from theprocess described in said patent No. 110,998, and from patent No.86,803, issued to Gideon Bantz, February 9, 1869, from the fact thesteam, as well as the water, passes through the charge. There wateralone passes through. This process is preferable, for oils almostinsoluble in water. By opening gate h in E, and letting on steam by jetF, I cause the steam to circulate, thus employing the second part ofthis invention. To cool exhausted. charge I remove cover a, put on K,and let on steam to jet F, and keep it on till charge is cooled orremoved. This jet draws air down through charge, up E, and discharges itat remote end of K. The water in 0 pre vents air entering A by B.

To use with teaberry, I fill A half full with water, open gate in r, anduse, as described in said patent No. 110,998, until three-fourths of oilare extracted, then draw off water by 8, close gate in r, and extractthe remainder by circulating steam.

By adding an extra steam-jet, F, pointing downward to the heater of astill constructed as described in Fig. 1, said patent No. 110,998, Imake a cheaper, but less convenient still. To use I partly fill withwater, and use as there described for preliminary treatment, then drawoff water and let on steam by the extra jet F, to extract oil bycirculating steam.

The preliminary treatment by boiling can be accomplished in metallicvessels -over fire or in tanks heated by steam-coils but I consider thisa less convenient mode. Again, the steam may be caused to circulate byfanblowers; but I consider it less convenient than by steam-jets. Theair used to cool exhausted charge may be drawn down through charge by anexhaust-fan or by a column of falling water, as in the trombe orBunsensair-pump.

Oil has been extracted by passing steam into tanks containing charge andwater; but this process is much inferior to mine, for the waterinterferes with the free circulation of the steam.

In describing Fig. 5, said patent No. 120,596, I described, butexpressly disclaimed, a modification of the first part of thisinvention.

The heater described in said patent N 0. 110,998, Fig. 1, differs fromthe steam-circulator here claimed in the important point that thesteam-jet e in the former points toward pipe B leading to condenser,whereas in the latter the jet F points away from corresponding pipe B.Should any one, after drawing oil the water, attempt to use the heaterfor a steam-circulator, part of the steam might pass to the condenserwithout ever passing through charge.

All the claims in said two patents Nos. 110,998 and 120,596 are in allcases to take precedence to the claims in the present application, incase they conflict.

The first, second, and fourth parts of my invention differ from theprocess and apparatus described in said patent 86,803, issued to GideonBantz, February 9, 1869, in this among other important points, viz: Ipass the impregnated steam to condenser from the end of the stillopposite to that by which it is admittedto charge; while he passes itfrom the same end by which it is admitted. Therefore, in my inventionthe whole of the steam must pass through charge once, and the bulk of itmany times. In his invention a few bubbles may be mechanically (to quotehis patent) carried down by the jets into the mass of water, and amongthe materials to be acted upon but the bulk of the steam does not passinto charge, and it is very doubtful if any passes through.

I do not claim the combination of a steamcirculator; nor of a steam-jet;nor of a hydraulic main; nor of a cooler with anything else than withstills for extracting essential oils; for I am aware that each of thefirst three have been combined with the other devices, such asbucking-kiers, leach-tubs, apparatus for treating corn, gas-retorts, 8m.

What I claim as my invention is- 1. The process of extracting essentialoils by first giving the charge a preliminary treatment with hot water,andthen passing steam through charge after having drawn OK this water.

2. Giving a circulatory movement to the steam used to extract the oil,so that some portions of this steam may pass through same charge morethan once.

3. Cooling exhausted charge by drawing air down through it.-

4. The combination of a still for essential oils and thesteam-circulator E- F, or its equivalent, for the purpose set forth.

5. The combination of a still for essential oils and the cooler E K L,Fig. 1, or E F K, Fig.h 2, or their equivalents, for the purpose setfort 6. The combination of one or more stills for essential oils and ahydraulic main; all substantially as and for the purposes hereinbeforedescribed.

GEORGE GILMAN PEROIVAL.

Witnesses:

ISABEL B. PERCIVAL, 1 JAMES H. PLAIsTED.

